We'd like to add other widgets to our Marble window: A zoom slider and a label that shows the current mouse position.

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We'd like to add other widgets to our Marble window: A '''zoom slider''' and a '''label''' that shows the current mouse position in '''geodetic''' coordinates: ''longitude'' and ''latitude''.

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In order to achieve this we need to create a vertical layout. Once done we add the slider and the label that we created to the layout. Also we zoom the globe to the slider's default value using the [http://api.kde.org/4.x-api/kdeedu/marble/classMarble_1_1MarbleWidget.html#d49d8ab0be0721c579bb511bdda45829 MarbleWidget::zoomView(int)] method.

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In order to achieve this we need to create a vertical layout. Once we are done we add the slider and the label that we created to the layout. Also we zoom the globe to the slider's default value using the [http://api.kde.org/4.x-api/kdeedu-apidocs/marble/html/classMarble_1_1MarbleWidget.html#d49d8ab0be0721c579bb511bdda45829 MarbleWidget::zoomView(int)] method.

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We want to center our globe onto South America. So we create a new [http://api.kde.org/4.x-api/kdeedu/marble/classMarble_1_1GeoDataCoordinates.html GeoDataCoordinates] object that takes the longitude and the latitude as a parameter and we call [http://api.kde.org/4.x-api/kdeedu/marble/classMarble_1_1MarbleWidget.html#7cda9942ead26d60c89a7b54a073a2fd MarbleWidget::centerOn].

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We want to center our globe onto South America. So we create a new [http://api.kde.org/4.x-api/kdeedu-apidocs/marble/html/classMarble_1_1GeoDataCoordinates.html GeoDataCoordinates] object that takes the longitude and the latitude as a parameter and we call [http://api.kde.org/4.x-api/kdeedu-apidocs/marble/html/classMarble_1_1MarbleWidget.html#7cda9942ead26d60c89a7b54a073a2fd MarbleWidget::centerOn].

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As you might have realized already GeoDataCoordinates is the geodetic "sister" of [http://doc.trolltech.com/qapplication.html QPoint]. They share a very similar API. Additionally GeoDataCoordinates features a nice set of string conversion methods ([http://api.kde.org/4.x-api/kdeedu-apidocs/marble/html/classMarble_1_1GeoDataCoordinates.html#ce27e6f714e21be067995c2cf96544d6 GeoDataCoordinates::fromString()], [http://api.kde.org/4.x-api/kdeedu-apidocs/marble/html/classMarble_1_1GeoDataCoordinates.html#558b72384563190dc2ce119a1f75de86 GeoDataCoordinates::lonToString()] and [http://api.kde.org/4.x-api/kdeedu-apidocs/marble/html/classMarble_1_1GeoDataCoordinates.html#558b72384563190dc2ce119a1f75de86 GeoDataCoordinates::latToString()]). They are used in various places inside Marble such as the signal [http://api.kde.org/4.x-api/kdeedu-apidocs/marble/html/classMarble_1_1MarbleWidget.html#0869df8f4666014aff93d9ba1c130bc3 MarbleWidget::mouseMoveGeoPosition(const QString&) ].

Finally we connect the [http://doc.trolltech.com/signalsandslots.html signals and slots] that MarbleWidget offers to the signals and slots of the slider and the label:

Finally we connect the [http://doc.trolltech.com/signalsandslots.html signals and slots] that MarbleWidget offers to the signals and slots of the slider and the label:

Revision as of 15:56, 13 January 2013

Creating a window with controls

We'd like to add other widgets to our Marble window: A zoom slider and a label that shows the current mouse position in geodetic coordinates: longitude and latitude.

In order to achieve this we need to create a vertical layout. Once we are done we add the slider and the label that we created to the layout. Also we zoom the globe to the slider's default value using the MarbleWidget::zoomView(int) method.

Finally we connect the signals and slots that MarbleWidget offers to the signals and slots of the slider and the label:

#include <QtGui/QApplication>#include <QtGui/QLayout>#include <QtGui/QSlider>#include <QtGui/QLabel>#include <marble/MarbleWidget.h>usingnamespaceMarble;intmain(intargc,char**argv){QApplicationapp(argc,argv);QWidget*window=newQWidget;// Create a Marble QWidget without a parentMarbleWidget*mapWidget=newMarbleWidget();// Load the Plain mapmapWidget->setMapThemeId("earth/plain/plain.dgml");// Hide the FloatItems: OverviewMap, ScaleBar and CompassmapWidget->setShowOverviewMap(false);mapWidget->setShowScaleBar(false);mapWidget->setShowCompass(false);// Create a horizontal zoom slider and set the default zoomQSlider*zoomSlider=newQSlider(Qt::Horizontal);zoomSlider->setMinimum(1000);zoomSlider->setMaximum(2400);mapWidget->zoomView(zoomSlider->value());// Create a label to show the geodetic positionQLabel*positionLabel=newQLabel();positionLabel->setSizePolicy(QSizePolicy::Preferred,QSizePolicy::Fixed);// Add all widgets to the vertical layout.QVBoxLayout*layout=newQVBoxLayout;layout->addWidget(mapWidget);layout->addWidget(zoomSlider);layout->addWidget(positionLabel);// Center the map onto a given positionGeoDataCoordinateshome(-60.0,-10.0,0.0,GeoDataCoordinates::Degree);mapWidget->centerOn(home);// Connect the map widget to the position label.QObject::connect(mapWidget,SIGNAL(mouseMoveGeoPosition(QString)),positionLabel,SLOT(setText(QString)));// Connect the zoom slider to the map widget and vice versa.QObject::connect(zoomSlider,SIGNAL(valueChanged(int)),mapWidget,SLOT(zoomView(int)));QObject::connect(mapWidget,SIGNAL(zoomChanged(int)),zoomSlider,SLOT(setValue(int)));window->setLayout(layout);window->resize(400,300);window->show();returnapp.exec();}